Add comprehensive documentation for CLICD features and operations

- Introduced Container Management documentation covering lifecycle operations, resource management, and console access.
- Added Dashboard documentation detailing metrics and related APIs.
- Created Host Report documentation summarizing host environment and resource status.
- Included Image Management documentation for template handling and management actions.
- Documented Networking and Routing features including NAT4 and IPv6 management.
- Added Security Alerts documentation outlining alert scenarios and API usage.
- Created Snapshot Management documentation for snapshot operations and scheduling.
- Documented Sub-user management for granting access to specific containers.
- Added Configuration guide detailing runtime settings and security recommendations.
- Created Installation guide for setting up CLICD with requirements and steps.
- Added Introduction and Quick Start guides for new users.
- Documented Upgrade process with version checking and pre-upgrade checklist.
- Created Deployment guide for service exposure and firewall recommendations.
- Added FAQ section addressing common questions and concerns.
- Documented Troubleshooting steps for common issues encountered.

docs/en/guide/configuration.md

@@ -0,0 +1,30 @@
+# Configuration
+
+After installation, CLICD runs as a systemd service. Runtime configuration and the database are stored locally on the host. The exact path may vary with installer options, but the default installation should mainly be checked under `/root/.clicd/`.
+
+## Common Settings
+
+| Setting | Description |
+| --- | --- |
+| Web port | Defaults to `8999`, listening on `0.0.0.0:8999`. |
+| Administrator account | Used to log in to the web panel and manage API keys. |
+| Database | SQLite storage for container metadata, sub-users, audit logs, API keys, and more. |
+| NAT port range | Used for random ports and port mapping allocation. |
+| IPv6 prefixes | Used when the host has routable IPv6 prefixes. |
+| Security alerts | Policies such as automatic shutdown can be configured. |
+
+## Service Commands
+
+```bash
+systemctl status clicd
+systemctl restart clicd
+journalctl -u clicd -n 100 --no-pager
+```
+
+## Security Recommendations
+
+- Do not expose the web panel directly to untrusted networks.
+- Use a strong administrator password and rotate it regularly.
+- Split API keys by purpose and avoid long-lived full-access keys.
+- WebSSH and WebVNC tickets are short-lived credentials and should not be written to logs or shared publicly.
+- Do not paste real IPs, passwords, API keys, or tickets into public docs, screenshots, or support tickets.